Aortic valve replacement via mini-sternotomy versus full sternotomy: a single centre retrospective cohort study

Background: The traditional method of aortic valve replacement (AVR) is via full sternotomy. However, this incision may not heal properly and cause significant pain. Minimally-invasive methods have been adopted, including mini-sternotomy, gaining popularity due to a smaller incision, reducing surgical trauma. The hypothesis is that AVR via mini-sternotomy is a safe alternative to full sternotomy. Methods: This retrospective study compares 2 groups; AVR via mini- and via full sternotomy. Inclusion criteria were all patients 18 and over who underwent AVR between September 2016 and December 2022 in Cork University Hospital. Patients who underwent concomitant cardiac procedures were excluded. Statistical analysis was performed using STATA software. Continuous data was analysed using the student t-test. Categorical data was analysed using the Pearson chi-squared test. A p value of <0.05 was deemed statistically significant. Results: 169 patients were included; 96 and 73 in the mini- and full sternotomy groups, respectively. Groups were well matched in terms of baseline characteristics including age, BMI, and co-morbidities. The mini-sternotomy group showed a statistically significantly shorter hospital length of stay (t(166)=4.24, p=0.000). There were no statistically significant differences in intra- (t(167)=1.8, p=0.067) and post-operative blood transfusion requirements (t(167)=0.53, p=0.592). The mini-sternotomy group had significantly longer cross-clamp (t(167)=-2.1, p=0.039) and cardio-pulmonary bypass times (t(167)=-2.45, p=0.015). Conclusion: AVR via mini-sternotomy has been associated with shorter hospital stay, with the drawback of increased cross-clamp and cardio-pulmonary bypass times. This retrospective study demonstrates mini-sternotomy as a safe alternative to full sternotomy, in the cohort studied.